Yes

Question 1

Even though those (relevant) items are not expensive

Answer 1

Walaupun barang2 tersebut tidak mahal

Question 2

Valuable to me, my favorite with a lot of wonderful sentiment (keepsake)

Answer 2

berharga bagi saya, kesayangan saya dengan penuh kenang2 an yang indah.

Question 3

Pls respond regarding telephone communication from me regarding the thing (unintentionally) left in a taxi

Answer 3

Mohon respon ttg komunikasi telepon dari saya ttg barang tertinggal di taksi

Question 4

Please respond to me soon if you have been able to contact that taxi driver

Answer 4

Mohon segera respon apakah sudah dapat kontak ke driver taksi tersebut

Question 5

and (he has been) informed about the existence of that thing

Answer 5

dan diberitahukan ttg keberadaan barang tersebu